Ouch, i feel your pain. I started to grind for my Rotv and i used the demon spots in Felwood and Azhara (Both very popular- so fighting for mobs) and i can say i got maybe 10 felcloth in 2weeks, loads of hours. the drop rate is poor i would advise buying the felcloth cos you could grind from 54-60 on those dmeons and get maybe 25 pieces

. I gave up on my Rotv cos of the mats and that felheart was so easily available.
keep on grind'n partner *snicker*